diff mbox

patch to fix PR63620

Message ID CAFULd4a8uu4YvPz_mO+RXQRrYUxpy9jYFCTWB58c-Yuy9dkhDw@mail.gmail.com
State New
Headers show

Commit Message

Uros Bizjak Nov. 9, 2014, 7:33 p.m. UTC 
On Sun, Nov 9, 2014 at 8:16 PM, Uros Bizjak <ubizjak@gmail.com> wrote:

>> The following patch solves PR63620.  The details can be found
>>
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63620
>>
>> The patch is more than just the problem solution.  It adds global live
>> analysis for pseudos when it is necessary (live info change on a BB
>> border triggers it).  The patch opens a door for global optimizations
>> and transformations in LRA and it will be also useful for performance
>> problems reported by people in coming LRA rematerialization.
>>
>> The impact on compiler time is insignificant about 0.3% on whole
>> SPEC2000 compilation (and about the same on a compilation of 500K
>> lines FORTRAN file).
>>
>> The patch was successfully bootstrapped on x86/x86-64, ppc64, and ARM and tested on
>> x86/x86-64 and ppc64.
>
> Did you also try to bootstrap with r216987 [1] reverted? This revision
> adds a workaround for this problem on i686.
>
> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63620#c24

Unfortunately, the patch doesn't fix the original problem when
mentioned revision is reverted. I have attached patch to the message.

The testcase from the PR that fails to reload PIC register is:

--cut here--
/* { dg-do compile { target i?86-*-* } } */
/* { dg-options "-O2 -mfpmath=sse -msse -fPIC" } */

static const __float128 cf = 0.1E+30Q;

typedef __float128 (*func)(__float128 x);

__float128
test (__float128 x, int p, func f)
{
  x = f (x);
  if (p)
    x = f (cf);
  return x;
}

/* { dg-final { scan-assembler "get_pc_thunk" } } */
--cut here--

Uros.
diff mbox

Patch

Index: config/i386/i386.md
===================================================================
--- config/i386/i386.md	(revision 217269)
+++ config/i386/i386.md	(working copy)
@@ -2783,11 +2783,7 @@ 
 (define_insn "*pushtf"
   [(set (match_operand:TF 0 "push_operand" "=<,<")
 	(match_operand:TF 1 "general_no_elim_operand" "x,*roF"))]
-  "(TARGET_64BIT || TARGET_SSE)
-   && (!ix86_use_pseudo_pic_reg ()
-       || !can_create_pseudo_p ()
-       || GET_CODE (operands[1]) != CONST_DOUBLE
-       || standard_sse_constant_p (operands[1]))"
+  "TARGET_64BIT || TARGET_SSE"
 {
   /* This insn should be already split before reg-stack.  */
   gcc_unreachable ();
@@ -2813,10 +2809,7 @@ 
 (define_insn "*pushxf"
   [(set (match_operand:XF 0 "push_operand" "=<,<")
 	(match_operand:XF 1 "general_no_elim_operand" "f,Yx*roF"))]
-  "!ix86_use_pseudo_pic_reg ()
-   || !can_create_pseudo_p ()
-   || GET_CODE (operands[1]) != CONST_DOUBLE
-   || standard_80387_constant_p (operands[1]) > 0"
+  ""
 {
   /* This insn should be already split before reg-stack.  */
   gcc_unreachable ();
@@ -2848,13 +2841,7 @@ 
 (define_insn "*pushdf"
   [(set (match_operand:DF 0 "push_operand" "=<,<,<,<")
 	(match_operand:DF 1 "general_no_elim_operand" "f,Yd*roF,rmF,x"))]
-  "!ix86_use_pseudo_pic_reg ()
-   || !can_create_pseudo_p ()
-   || GET_CODE (operands[1]) != CONST_DOUBLE
-   || (!(TARGET_SSE2 && TARGET_SSE_MATH)
-       && standard_80387_constant_p (operands[1]) > 0)
-   || (TARGET_SSE2 && TARGET_SSE_MATH
-       && standard_sse_constant_p (operands[1]))"
+  ""
 {
   /* This insn should be already split before reg-stack.  */
   gcc_unreachable ();